The present invention relates to a chamfering apparatus capable of chamfering the edge of the outer periphery of a work and, more particularly, to a chamfering apparatus capable of easily performing adjustment of the amount of chamfer, adjustment of the angle of chamfer, and exchange of a cutting tip, and efficiently collecting chips in a chip receptacle without scattering them around.
The arrangement of a known chamfering apparatus disclosed in Jpn. UM Appln. KOKAI Publication No. 3-57379 will be explained briefly. FIG. 9 is a sectional front view of chamfering apparatus; and FIG. 10 is a side view of the same.
Referring to FIGS. 9 and 10, a gripping portion 51 stores an electric motor. An elbow-like rotating shaft housing 52 is mounted on the distal end of the gripping portion 51 to face down. A bearing portion 53 is fixed in the lower portion of the rotating shaft housing 52 to face down. A cutting tip 56 is detachably mounted on the lower portion of a rotating shaft 55 vertically supported by a bearing 54 of the bearing portion 53.
The bearing portion 53 has a cylindrical outer circumferential surface. An eccentric ring 57 for adjusting the projection amount (amount of chamfer) of the cutting tip 56 is provided around the bearing portion 53 of the rotating shaft housing 52 to be rotatable about the bearing portion 53. The eccentric ring 57 has a cylindrical outer circumferential surface which is eccentric with respect to its inner circumferential surface. A fixing bolt 58 fixes the bearing portion 53 and eccentric ring 57. Around the eccentric ring 57, a support bracket 59 having a boss is rotatably disposed on the lower end side of the eccentric ring 57. An auxiliary knob 60 and a guide plate 63 are attached to the support bracket 59. The guide plate 63 is formed of a vertical plate 61 and horizontal plate 62 that extend perpendicularly in an L-shape, to constitute a guide surface movable along a work surface. A slit is formed in the support bracket 59. When a fastening bolt 64 provided to this slit is tightened, the support bracket 59 can be fixed to the eccentric ring 57. An opening 65 is formed in the narrow angle of the perpendicularly intersecting portion of the guide plate 63. The cutting tip 56 at the lower end portion of the rotating shaft 55 can be seen through this opening 65.
The function of the chamfering apparatus having the above arrangement will be described. When the power cord is connected to the power supply and the switch is turned on, the cutting tip 56 rotates. The guide plate 63 is used to guide the corner portion of a work 70. The cutting tip 56 is set to oppose the ridge portion of the work 70 from the side surface. When the chamfering apparatus is moved, the ridge portion is chamfered.
When the fastening bolt 64 is loosened and the support bracket 59 is rotated with respect to the eccentric ring 57, the guide plate 63 moves forward/backward in the directions of arrows A and B in accordance with the degree of eccentricity. Hence, the amount of chamfer can be adjusted.
While the fixing bolt 58 is loosened and the fastening bolt 64 is fastened to fix the support bracket 59 on the eccentric ring 57, when the eccentric ring 57 is pivoted, the support bracket 59 attached with the guide plate 63 and auxiliary knob 60 can be pivoted about the axis of the cutting tip 56 both clockwise and counterclockwise. As a result, the directions of the guide plate 63 and auxiliary knob 60 can be freely changed to facilitate operation.
In the above chamfering apparatus, when the amount of chamfer is to be adjusted, the fixing bolt 58 must be loosened and thereafter the eccentric ring 57 must be rotated around the bearing portion 53, making it cumbersome to adjust the amount of chamfer. When the eccentric ring 57 is rotated in order to adjust the amount of chamfer, the angle the gripping portion 51 of the motor makes with the support bracket 59 sometimes changes inadvertently. As a result, to obtain an optimum angle of the auxiliary knob 60 and gripping portion 51 after the amount of chamfer is adjusted, the angle of the gripping portion 51 must be adjusted again.
The angle of chamfer is also adjusted by exchanging the cutting tip 56. Hence, adjusting the angle of chamfer is difficult to perform.
When the cutting tip 56 wears out and need be exchanged, it cannot be exchanged unless the support bracket 59 is removed, resulting in a cumbersome tip exchange operation.
Since this apparatus does not have a chip receptacle for collecting chips generated during machining, the chips scatter around, which is not preferable in terms of environment.